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ay domains of life. The present bioinformatics and phylogenetic analysis shows that HLR DNA glycosylase superfamily members in the genus Bacillus form three subfamilies: AlkC, AlkD and AlkF/AlkG. The crystal structure of AlkF shows structural similarity with the DNA glycosylases AlkC and AlkD, however neither superfamilies (Berti and McCann, 2006; Stivers and Jiang, 2003; ted 3D structure, et al., 2007), and graphy (Ru solved in c with DNA, demonstrating a novel lesion capture mechanism, ently not involving base flipping (Rubinson et al., 2010). Here we present a clustering analysis suggesting that the discovered HLR DNA glycosylase superfamily can be categorized into three subfamilies: AlkC, AlkD and AlkF/AlkG. Unexpectedly, biochemical and genetic analysis demonstrates that AlkF and AlkG possess no DNA glycosylase activity. Instead these proteins bind branched DNA, such as Holliday junctions (HJ) and 3-way junctions (3WJ). A crystal structure of AlkF without DNA and a computer model of the protein in complex with DNA, suggest a model for DNA binding which is unique for the AlkF/AlkG family. q This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-No Derivative Works License, which per-mits non-commercial use, distribution, and reproduction in any medium, provide